EdkCompatibilityPkg/Foundation/Library/EdkIIGlueLib/Library/BaseLib/X64/WriteMsr64.asm

   1 ; Copyright (c) 2004, Intel Corporation
   2 ; All rights reserved. This program and the accompanying materials
   3 ; are licensed and made available under the terms and conditions of the BSD License
   4 ; which accompanies this distribution.  The full text of the license may be found at
   5 ; http://opensource.org/licenses/bsd-license.php
   6 ;
   7 ; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
   8 ; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
   9 ;
  10 ; Module Name:
  11 ;
  12 ;   WriteMsr64.Asm
  13 ;
  14 ; Abstract:
  15 ;
  16 ;   AsmWriteMsr64 function
  17 ;
  18 ; Notes:
  19 ;
  20 ;------------------------------------------------------------------------------
  21
  22     .code
  23
  24 ;------------------------------------------------------------------------------
  25 ; UINT64
  26 ; EFIAPI
  27 ; AsmWriteMsr64 (
  28 ;   IN UINT32  Index,
  29 ;   IN UINT64  Value
  30 ;   );
  31 ;------------------------------------------------------------------------------
  32 AsmWriteMsr64   PROC
  33     mov     rax, rdx                    ; meanwhile, rax <- return value
  34     shr     rdx, 20h                    ; edx:eax contains the value to write
  35     wrmsr
  36     ret
  37 AsmWriteMsr64   ENDP
  38
  39     END